After late deliveries of voting materials, Ugandans waited in the unbearable heat to vote in the Ugandan presidential and parliamentary elections amid claims by the main opposition party that the delays were deliberate and in favour of current president Yoweri Museveni (NRM).

At 12pm, with more than 15 million people registered to vote, including members of parliament as well as the president himself, polling stations were experiencing a waiting time of five hours, and some polling stations in the Ugandan capital of Kampala had still not received their ballot boxes. The boxes, which had arrived at certain polling stations, came mid-morning, but with still no ballots cast, people were left to form long lines, sweltering in the heat. At other polling stations in Kampala, the wait to vote was reported to be taking up to seven hours, with reports of people being told that votes were only to be cast for choosing members of parliament, not for the voting of a president.

"These cases are worrying because every citizen of Uganda has the right to vote," said Eduard Kukan, chief of the European Union's election observer mission. "And if they are prevented by this kind of method then it would have to be criticised, because it would mean that they didn't manage the organising of the elections in the right way."

Many of those waiting said they would refuse to leave without voting."This is very disappointing but I am going to stay here under the sun until it is my turn to vote," said Fred Mubiru, a taxi driver. "Nothing will discourage me."

People from the Karamojong tribe wait in line to vote during elections in a village near Kaabong District, Uganda Goran Tomasevic/ ReutersSome areas were experiencing a delay of up to five hours to vote as people were forced to wait in the blistering heatGoran Tomasevic/ ReutersA Karamojong tribeswoman casts her ballot during the presidential elections in Kaabong District, UgandaGoran Tomasevic/ ReutersA Karamojong tribesman sits as he waits to vote in the Karamoja region, UgandaGoran Tomasevic/ Reuters

The spokesman for Kizza Besigye's party, the Forum for Democratic Change, said the delivery delays were a "deliberate attempt to frustrate" voters in urban areas where Besigye is believed to be very popular, especially Kampala and the neighbouring district of Wakiso. The seven opposition candidates are striving to beat the current president, fearing that violence could affect the vote, with the leading opposition candidates predicting that ballots will be rigged.

"Such a day is highly undermined by the lack of free and fair elections," opposition candidate Kizza Besigye said, as he cast his vote in Rukungiri village in western Uganda. Besigye has run unsuccessfully in three previous elections.

Museveni, 71, came to power in 1986 after waging a five-year guerrilla war, yet many Ugandans now credit him with providing peace and economic stability. Yet many of Uganda's younger voters blame Museveni for not tackling endemic corruption or creating enough jobs, and want change. "We are so far behind. We need to open our eyes and move into the 'now' tense," Joel Nyonyintono, a 26-year-old entrepreneur said as he sat near a church in Kampala.

"We have had peace for a long time and these young people are taking it for granted because they don't know how it was before," she said, referring to years when Uganda was ruled by two dictators infamous for unpredictable violence.

A Ugandan reads a newspaper in the countdown to the presidential elections which have been mired in controversy and claims of vote riggingIsaac Kasamani/ AFPA polling assistant issues a ballot paper to a voter in Kiruhura District, west UgandaJames Akena/ ReutersMore than 15 million people have registered to vote for their next president in the Ugandan electionsGoran Tomasevic/ ReutersA Karamojong tribeswoman casts her ballot Goran Tomasevic/ ReutersBy 12pm on voting day, some areas had yet to receive ballot boxesGoran Tomasevic/ ReutersYounger voters say incumbent president Yoweri Museveni has failed to deal with widespread corruption and unemploymentGoran Tomasevic/ ReutersA woman casts her ballot in a polling station in Kirihura, west UgandaJames Akena/ ReutersA woman shows her thumb marked with ink moments after casting her vote in Mukono District, east of KampalaIsaac Kasamani/ AFPAn electoral commission worker sits by a polling station moments before voting begins in Kaabong DistrictGoran Tomasevic/ ReutersA police officer casts his ballot in a village near Kaabong DistrictGoran Tomasevic/ ReutersA lone ballot box is seen just before the vote in the Karamoja region, UgandaGoran Tomasevic/ Reuters

People form a huge queue at the Nasuti polling station in Mukono District, near KampalaCarl de Souza/ AFP

Ugandans at the Nasuti polling station in Mukono DistrictIsaac Kasamani/ AFPPeople follow live TV coverage of the Ugandan vote near the Nasuti polling station in Mukono District, UgandaIsaac Kasamani/ AFPJames, a kite vendor flies a kite at rush hour while wearing the Ugandan flag in Kampala prior to the first-round electionsIsaac Kasamani/ AFPUgandans spend hours in a queue to cast their vote in KampalaCarl de Souza/ Getty Images